Housing New Zealand has had to hire almost the same number of staff to run its new call centre as it made redundant to set up its "more efficient" system, figures obtained by Labour show.

In April, the state corporation changed the way it operated, shutting its local office doors to its 200,000 tenants and members of the public with accommodation emergencies, and directing inquiries through a new customer service call centre.

The changes led to 70 frontline positions being axed.

The centre was touted as being able to cope with 1million calls a year but has failed to keep up with demand after receiving 119,000 calls in April alone, 53,000 of which went unanswered.

Labour housing spokeswoman Annette King said answers she received from Housing Minister Phil Heatley showed the corporation had been forced to employ 68.5 additional staff for the call centre.

"All they have done is shuffle jobs from one area to another. But it doesn't stop there: there is going to be even more employed."

Housing NZ yesterday apologised for waiting times of up to 40 minutes, although Mr Heatley has said the average waiting time was about eight minutes.

Ms King said problems with the call centre were exacerbated by housing advocates, social workers and even maintenance contractors also being instructed to use the 0800 number.

Mr Heatley had set up a separate line for maintenance contractors.

Lifewise manager Corie Haddock said in the past the Auckland-based Methodist social services had a single point of contact at Housing NZ, but were now told to use the new call centre.

"Without any real consultation at all, ... were required to contact them through the 0800 number like everyone else."

Fairfax Media revealed earlier this week that one housing advocate had become so frustrated with being unable to get through to Housing NZ, he had put a vulnerable family in his car and taken them to the back door of a Housing NZ office for help.

A Housing NZ spokeswoman said "key stakeholders" had been given direct dial numbers.

"If we have inadvertently not communicated with these groups then I suspect it is just a mistake and we would like to know who they are so we can make contact."

Ms King said electorate staff even in National MPs' offices had been flooded with requests for help from constituents with housing issues because they couldn't go to a Housing NZ office or get through to the call centre.

"MPs' staff, particularly in Auckland, are telling their MPs they cannot cope with the workload."

Public Service Association national secretary Brenda Pilott said staff tried to warn Housing NZ the change was happening too quickly.